// Copyright 2019 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

package botanist

import (
	"context"
	"os/exec"
	"syscall"
)

// Run runs a command until completion or until a context is canceled, in
// which case the subprocess is killed so that no subprocesses it spun up are
// orphaned.
func Run(ctx context.Context, cmd exec.Cmd) error {
	cmd.SysProcAttr = &syscall.SysProcAttr{Setpgid: true}
	if err := cmd.Start(); err != nil {
		return err
	}
	done := make(chan error)
	go func() {
		done <- cmd.Wait()
	}()

	select {
	case err := <-done:
		return err
	case <-ctx.Done():
		syscall.Kill(-cmd.Process.Pid, syscall.SIGKILL)
		return ctx.Err()
	}
}